Help Identify IC for SoundMixer PSU

[cyblaz]

Hi,
The Power Supply of my Sound Mixer broked and I try my fix. The output of the PSU is + 48V, + 15V, -15V and 5V DC.
I check the DC voltage on the bride diode to the input of the tranformer Bride is good, only the output from the IC that does not exist. I assume the IC is damaged. but the type in this ic has been wiped. Does anyone know what kind of IC's
sorry for my bad english .TIA,

 

[davenn]

hi cyblaz
welcome to EP

what make and model is it ?
have you tried googling for circuits, manual ?


Dave

 

[shrtrnd]

And are there any markings on that IC? I can't tell from the pictures.

 

[cyblaz]

hi cyblaz
welcome to EP

what make and model is it ?
have you tried googling for circuits, manual ?
Dave

Hi davenn,
I've searched on google and found the manual that contains the schematic, but i think its a little different from my psu.
CMIIW, In the schematic that I get, GND (-) is connected to pin 5 of IC but on my PSU GND (-) is connected to pin 3.
It seems that both have the same functions with additional control on the IC that is in my PSU.

Here's the schematic i'v got.

And are there any markings on that IC? I can't tell from the pictures.

I don't see any mark and I think it was intentional (?)


Any sugest ?

 

[shrtrnd]

I've spent 1/2 an hour trying to get a good print of your schematic so I can read it, with no luck.
It'll be tough to ID the exact IC without markings, but I can't see enough on the schematic to even hazard a guess at the IC's function.
Can you enlarge the section of the schematic in question?

 

[bsco]

Looks like a 3842A.....power control IC....I had a look at you schematic with a magnifer.....google 3842 IC data sheet and have a look.....also, if you can remove the chip and look at in on an angle, you might be able to see some markings.....